Technical Field
The present invention relates to a force sensing module, especially related to a force sensor adaptive to be used in an electronic pen or other electronic devices.
Description of Related Art
FIG. 1 shows a prior art electronic pen.
FIG. 1 shows an electronic pen 10 which includes a pen tip 13 and an optical sensor. The optical sensor 14 is configured on a bottom of the pen tip 13 for sensing a pressure applied against the pen tip 13. A printed circuit board 15 is configured on a bottom of the optical sensor 14 for processing the signal information sensed at the optical sensor 14 and then transmits a corresponding signal to a display. A battery 16 is configured on a bottom of the printed circuit board 15 to provide energy for powering the electronic pen 10.
The disadvantage for the prior art is that the complicated system uses optical sensor 14 which is always active. In order to save battery power, a more energy efficient pressure sensing mechanism producing larger signal change in a compact form factor is desired. This could be achieved using a combination of force sensors and force sensitive switches in a single electronic pen device